C.V.
If one of my kids has a party like that I always put on the invite something like,pizza and tokens will be provided for the child on the invite,or "john" will be paid for...the rest of the family is welcome to come the cost is $5,or "suzy" and "sally's bowling is included in the part if anyone else wants to bowl it will be $6...
So no I do not think it's inappropriate at all.I have only had a problem one time and that was my Husband's fault.He was told to meet the guests at the door with their tickets (it was cheaper for me to add everyone to the party and have them pay me.) Only problem was he didn't collect the money from them,he just gave them their tickets.So I have never again added anyone to my party,they have to pay at the door if they want to participate!